Patent GB-1407591-A (GB)
Title: Suspension systems for vehicle seats
IPC: B60N2/54
Filed: 1971-11-27
Abstract: 1407591 Resilient mountings UNIVERSAL OIL PRODUCTS CO 20 Nov 1972 [27 Nov 1971] 55164/71 Heading A4U [Also in Division F2] A suspension system for a vehicle seat comprises seat-supporting pivotally mounted arms 6, 10 which are biased upwardly by spring assemblies 16, 40 each including two concentric members 18 and 22, 42 relatively rotatable upon movement of the arms, an elastic body 20 interposed between the members 18 and 22, 42 being resiliently deformable by such relative rotation caused by downward movement of the seat, the spring assembly 40 being selectively placed in or out of an operational state by a spring-loaded lever 46 being engaged with or disengaged from an abutment 44 on the member 42. The arms 6, 10 form crossed-arm linkages and are pivotally connected at their intersections by a pivot bar 14. Each arm 6 extends from a pivot shaft 15 on a base frame 4 to a horizontally sliding pivotal connection 8 on a seatsupporting frame 2, and each arm 10 extends from a horizontally sliding pivotal connection 12 on the frame 4 to a shaft which forms the member 18 and which is rigidly connected to the arms 10 and is journalled in the frame 2. The body 20 of the assembly 16 may be of rubber and it is bonded to the members 18 and 22, the member 22 being locked against rotation relative to the frame 2 by a device 26 which is adjustable for varying the bias or pre-load characteristics of the spring assembly. The device 26 comprises a screw connected to a handle and engaged with a nut carried by lugs rigid with and extending radially from the member 22, Fig.3 (not shown). A shock absorber 24 is connected between the frames 2 and 4. The spring assembly 40 acts in parallel with the spring assembly 16. In a modification, Fig.4 (not shown), the members 18 and 22 or 42 are of square crosssection and are angularly offset, and four elastic inserts are interposed between the faces of the member 18 and the respective opposed corners of the member 22 or 42, each elastic insert being of circular cross-section when unstressed. In another embodiment, Fig.5 (not shown), two spring assemblies (52, 54) are inter-connectible to operate in series. One spring assembly (52) comprises an elastic sleeve bonded at its inner surface to the shaft 18 and at its outer surface to a cylindrical housing (56), and the other spring assembly (54) comprises a tubular member rotatably mounted on the shaft 18 and an elastic sleeve bonded at its inner surface to the tubular member and at its outer surface to a cylindrical housing (58) which is locked against rotation relative to the frame 2 by a bias-varying device similar to the device 26. An arm (60) which is rotatable about the shaft 18 is rigidly secured to the cylindrical housing (56) of the said one spring assembly (52) and to the tubular member of the said other spring assembly (54) to couple the spring assemblies in series. The said other spring assembly (54) is selectively rendered inoperative by a rod (62) which is slidable in a collar (64) carried by the cylindrical housing (58) of the said other spring assembly (54) and is spring-biased into engagement with an aperture in the arm (60) to secure the tubular member and the cylindrical housing (56) of that spring assembly against relative rotation. The rod (62) is retracted against the spring bias and held in its retracted position to render the said other spring assembly (54) operative.